Sony PD100 - 'Back Focus' Problem

[grant mcphee]

Hello,

 

I've got an old PD100 which I'm convinced has a back focus problem.

 

Obviously there is no external way to change the back focus in the way you would with a camera with changeable lenses - digibeta etc.

 

I zoom in, get a sharp, slowly zoom out and the image looks a little soft on the wide end. f I use the 'push auto' button I get it sharp, then when I zoom in the image is completely out at the long end.

 

I've had a similar problem with a Z1 where, after the lens was repaired the engineer had done something which resulted in the back focus being out.

 

Any ideas how I can repair this myself without spending a few hundred pounds at an engineers?

 

Thanks